I fold because of gap concept.
Plus you have a full rotation at 10.5 BBs to find a better spot to get it in.
This, but OP, what sort of read do you have on villain? Some people are nits with 9bb, some people shove any 2 if it's folded to them in middle or late position. (effectively, the hand was folded to villain since the 1bb UTG all-in is pretty negligible, except that the villain might have a slightly tighter range, knowing that he will be forced to show his hand and give out free information).
Also consider your own table image. If you're perceived to be loose, villain may think twice about shoving a weak hand on your blind. If you're perceived to be tight, villain will shove on your BB with a much wider range. If you're a nit? Any 2 will do.
If the A8 were suited I would think about it more but probably still fold. I do like that your ace is likely live in this case, but knowing that villain's range could be slightly tighter makes it a clear fold.
When you are calling all of your chips (in this case all but 2bb, same difference) you need a better hand than what you would open shove with. Often A8o is an open fold in early position with 11bb.
You are likely to have a spot with higher
equity before you reach the BB again, especially if you can find yourself in late position when the action has folded to you.